Feynman Quotes

Physics is like sex: sure, it may give some practical results, but that's not why we do it. ~ Richard Feynman

Science is a process for learning about nature in which competing ideas about how the world works are measured against observations. ~ Richard P. Feynman

All the evidence, experimental and even a little theoretical, seems to indicate that it is the energy content which is involved in gravitation, and therefore, since matter and antimatter both represent positive energies, gravitation makes no distinction. ~ Richard P. Feynman

Physics is to math what sex is to masturbation. ~ Richard Feynman

I happen to know this, and I happen to know that, and maybe I know that;and I work everything out from there. Tomorrow I may forgot that this is true, but remember that something else is true, so I can reconstruct it all again. I am never quite sure of where I am supposed to begin or where I am supposed to end. I just remember enough all the time so that as the memory fades and some of the pieces fall out I can put the thing back together again every day ~ Richard Feynman

The lay reader only wanted to have the illusion of understanding and to catch a few buzzwords to throw around at cocktail parties. ~ Richard P. Feynman

All our bright minds," Feynman said sardonically, "and we can't figure how to stop the enemy from dumping dirt on us." Freeman said with delicate precision, "We are hothouse flowers, really. Not made for the blunt edge of war." Nods ~ Gregory Benford

When I was a young man, Dirac was my hero. He made a breakthrough, a new method of doing physics. He had the courage to simply guess at the form of an equation, the equation we now call the Dirac equation, and to try to interpret it afterwards. ~ Richard P. Feynman

Throughout these lectures I have delighted in showing you that the price of gaining such an accurate theory has been the erosion of our common sense. We must accept some very bizarre behavior: the amplification and suppression of probabilities, light reflecting from all parts of a mirror, light travelling in paths other than a straight line, photons going faster or slower than the conventional speed of light, electrons going backwards in time, photons suddenly disintegrating into a positron-electron pair, and so on. That we must do, in order to appreciate what Nature is really doing underneath nearly all the phenomena we see in the world. ~ Richard Feynman

Raios cubicos!" he says, with a vengeance. Cube roots! ~ Richard Feynman

So far as we know, all the fundamental laws of physics, like Newton's equations, are reversible. ~ Richard P. Feynman

I think we should teach them [the people] wonders and that the purpose of knowledge is to appreciate wonders even more. ~ Richard Feynman

There in wine is found the great generalization: all life is fermentation. ~ Richard P. Feynman

The idea is to try to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another. ~ Richard P. Feynman

Physics is to mathematics like sex is to masturbation. ~ Richard Feynman

People who wish to analyze nature without using mathematics must settle for a reduced understanding. ~ Richard P. Feynman

That's the trouble with not being in your own field: You don't take it seriously. ~ Richard Feynman

If you want to win this argument with Dad, look in chapter two of the first book of the Feynman Lectures on Physics. There's a quote there about how philosophers say a great deal about what science absolutely requires, and it is all wrong, because the only rule in science is that the final arbiter is observation - that you just have to look at the world and report what you see. Um ... off the top of my head I can't think of where to find something about how it's an ideal of science to settle things by experiment instead of arguments - ~ Eliezer Yudkowsky

I practiced drawing all the time and became very interested in it. If I was at a meeting that wasn't getting anywhere - like the one where Carl Rogers came to Caltech to discuss with us whether Caltech should develop a psychology department - I would draw the other people. ~ Richard P. Feynman

There is also a rhythm and a pattern between the phenomena of nature which is not apparent to the eye, but only to the eye of analysis; and it is these rhythms and patterns which we call Physical Laws. What ~ Richard Feynman

I believe there's nothing in hallucinations that has anything to do with anything external to the internal psychological state of the person who's got the hallucination. ~ Richard P. Feynman

It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. How can all that be going on in that tiny space? Why should it take an infinite amount of logic to figure out what one tiny piece of space/time is going to do? ~ Richard Feynman

Architect of quantum theories, brash young group leader on the atomic bomb project, inventor of the ubiquitous Feynman diagram, ebullient bongo player and storyteller, Richard Phillips Feynman was the most brilliant, iconoclastic, and influential physicist of modern times. ~ James Gleick

When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.
The other students in the class interrupt me: "We *know* all that!"
"Oh," I say, "you *do*? Then no *wonder* I can catch up with you so fast after you've had four years of biology." They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes. ~ Richard Feynman

It is impossible, by the way, when picking one example of anything, to avoid picking one which is atypical in some sense. ~ Richard P. Feynman

The world is a dynamic mess of jiggling things ~ Richard P. Feynman

[Doubt] is not a new idea; this is the idea of the age of reason. This is the philosophy that guided the men who made the democracy that we live under. The idea that no one really knew how to run a government led to the idea that we should arrange a system by which new ideas could be developed, tried out, and tossed out if necessary, with more new ideas bought in - a trial-and-error system. This method was a result of the fact that science was already showing itself to be a successful venture at the end of the eighteenth century. Even then it was clear to socially minded people that the openness of possibilities was an opportunity, and that doubt and discussion were essential to progress into the unknown. If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar ... doubt is not to be feared, but welcomed and discussed. ~ Richard Feynman

Strange as it may seem, wrote Richard Feynman, we understand the distribution of matter in the interior of the Sun far better than we understand the interior of the Earth. ~ Bill Bryson

I don't think that the laws can be considered to be like God because they have been figured out. ~ Richard P. Feynman

If I get stuck, I look at a book that tells me how someone else did it. I turn the pages, and then I say, 'Oh, I forgot that bit,' then close the book and carry on. Finally, after you've figured out how to do it, you read how they did it and find out how dumb your solution is and how much more clever and efficient theirs is! ~ Richard P. Feynman

Study hard what interests you the most in the most undisciplined, irreverent and original manner possible. ~ Richard Feynman

The most obvious characteristic of science is its application: the fact that, as a consequence of science, one has a power to do things. And the effect this power has had need hardly be mentioned. The whole industrial revolution would almost have been impossible without the development of science. ~ Richard P. Feynman

It is odd, but on the infrequent occasions when I have been called upon in a formal place to play the bongo drums, the introducer never seems to find it necessary to mention that I also do theoretical physics. ~ Richard P. Feynman

Feynman resented the polished myths of most scientific history, submerging the false steps and halting uncertainties under a surface of orderly intellectual progress, but he created a myth of his own. ~ James Gleick

When the problem [quantum chromodynamics] is finally solved, it will all be by imagination. Then there will be some big thing about the great way it was done. But it's simple -it will all be by imagination, and persistence. ~ Richard P. Feynman

We need to teach how doubt is not to be feared but welcomed. It's OK to say, "I don't know." ~ Richard P. Feynman

You can't say A is made of B or vice versa. All mass is interaction. ~ Richard Feynman

Investigating the forces that hold the nuclear particles together was a long task. ~ Richard P. Feynman

Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and the relativity ideas are examples of this. ~ Richard P. Feynman

The game I play is a very interesting one. It's imagination, in a tight straightjacket. ~ Richard Feynman

You keep on learning and learning, and pretty soon you learn something no one has learned before. ~ Richard Feynman

When sunlight, which contains red, yellow, green, and blue light, shines on a mud puddle with oil on it, the areas that strongly reflect each of those colors overlap and produce all kinds of combinations which our eyes see as different colors ... This phenomenon of colors produced by the partial reflection of white light by two surfaces is called iridescence, and can be found in many places ... the more you see how strangely Nature behaves, the harder it is to make a model that explains how even the simplest phenomena actually work. ~ Richard Feynman

So our problem is to explain where symmetry comes from. Why is nature so nearly symmetrical? No one has any idea why. The only thing we might suggest is something like this: There is a gate in
Japan, a gate in Neiko, which is sometimes called by the Japanese
the most beautiful gate in all Japan; it was built in a time when
there was great influence from Chinese art. This gate is very elaborate,
with lots of gables and beautiful carving and lots of columns
and dragon heads and princes carved into the pillars, and so on.
But when one looks closely he sees that in the elaborate and complex
design along one of the pillars, one of the small design elements
is carved upside down; otherwise the thing is completely
symmetrical. If one asks why this is, the story is that it was carved
upside down so that the gods will not be jealous of the perfection
of man. So they purposely put an error in there, so that the gods
would not be jealous and get angry with human beings.
We might like to turn the idea around and think that the true
explanation of the near symmetry of nature is this: that God made
the laws only nearly symmetrical so that we should not be jealous
of His perfection! ~ Richard P. Feynman

This attitude of mind - this attitude of uncertainty - is vital to the scientist, and it is this attitude of mind which the student must first acquire. It becomes a habit of thought. Once acquired, we cannot retreat from it anymore. ~ Richard P. Feynman

I took a little walk outside for a while. I was surprised that I wasn't feeling what I thought people were supposed to feel under the circumstances. May be I was fooling myself. I wasn't delighted, but I didn't feel terribly upset, perhaps because we had known for a long time that it was going to happen.

It's hard to explain. If a Martian(who, we'll imagine never dies except by accident) came to Earth and saw this peculiar race of creatures-these humans who live about seventy or eighty years, knowing that death is going to come--it would look to hi like a terrible problem of psychology to live under those circumstances, knowing that life is only temporary Well, we humans somehow figure out how to live despite this problem: we laugh, we joke, we live.

The only difference for me and Arlene was, instead of fifty years, it was five years. It was only a quantitative difference--the psychological problem was just the same. The only way it would have become any different is if we had said to ourselves, "But those other people have it better, because they might live fifty years." But that's crazy. Why make yourself miserable saying things like, "Why do we have such bad luck? What has God done to us? What have we done to deserve this?"--all of which, if you understand reality and take it completely into your heart, are irrelevant and unsolvable. They are just things that nobody can know. Your situation is just an accident of life..

We had a hell of goo ~ Richard P. Feynman

The extreme weakness of quantum gravitational effects now poses some philosophical problems; maybe nature is trying to tell us something new here: maybe we should not try to quantize gravity. ~ Richard P. Feynman

Once we were driving in the midwest and we pulled into a McDonald's. Someone came up to me and asked me why I have Feynman diagrams all over my van. I replied, "Because I am Feynman!" The young man went, "Ahhhhh!" ~ Richard P. Feynman

If a piece of steel or a piece of salt, consisting of atoms one next to the other, can have such interesting properties; if water - which is nothing but these little blobs, mile upon mile of the same thing over the earth - can form waves and foam, and make rushing noises and strange patterns as it runs over cement; if all of this, all the life of a stream of water, can be nothing but a pile of atoms, how much more is possible? If ~ Richard Feynman

Einstein's gravitational theory, which is said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational phenomena with the geometry of space; this was an exciting idea. ~ Richard P. Feynman

If someone were to propose that the planets go around the sun because all planet matter has a kind of tendency for movement, a kind of motility, let us call it an 'oomph,' this theory could explain a number of other phenomena as well. So this is a good theory, is it not? No. It is nowhere near as good as the proposition that the planets move around the sun under the influence of a central force which varies exactly inversely as the square of the distance from the center. The second theory is better because it is so specific; it is so obviously unlikely to be the result of chance. It is so definite that the barest error in the movement can show that it is wrong; but the planets could wobble all over the place, and, according to the first theory, you could say, 'Well, that is the funny behavior of the 'oomph. ~ Richard Feynman

I think the educational and psychological studies I mentioned are examples of what I would like to call cargo cult science. In the South Seas there is a cargo cult of people. During the war they saw airplanes land with lots of good materials, and they want the same thing to happen now. So they've arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head like headphones and bars of bamboo sticking out like antennas - he's the controller - and they wait for the airplanes to land. They're doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn't work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they're missing something essential, because the planes don't land. ~ Richard Feynman

Western civilization, it seems to me, stands by two great heritages. One is the scientific spirit of adventure - the adventure into the unknown, an unknown that must be recognized as unknown in order to be explored, the demand that the unanswerable mysteries of the universe remain unanswered, the attitude that all is uncertain. To summarize it: humility of the intellect. ~ Richard Feynman

Few people realize the number of things that are possible. ~ Richard P. Feynman

Why are all the theories of physics so similar in their structure?

There are a number of possibilities. The first is the limited imagination of physicists: when we see a new phenomenon we try to fit it into the framework we already have-until we have made enough experiments, we don't know that it doesn't work.

Another possibility is that it is the same damn thing over and over again-that Nature has only one way of doing things, and She repeats her story from time to time.

A third possibility is that things look similar because they are aspects of the same thing- some larger picture underneath, from which things can be broken into parts that look different, like fingers on the same hand. Many physicists are working very hard trying to put together a grand picture that unifies everything into one super-duper model. It's a delightful game, but at the present time none of the speculators agree with any of the other speculators as to what the grand picture is. ~ Richard P. Feynman

You do not know anything until you have practiced. ~ Richard P. Feynman

There is a computer disease that anybody who works with computers knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is that you 'play' with them! ~ Richard P. Feynman

As usual, nature's imagination far surpasses our own, as we have seen from the other theories which are subtle and deep. ~ Richard P. Feynman

We get the exciting result that the total energy of the universe is zero. Why this should be so is one of the great mysteries - and therefore one of the important questions of physics. After all, what would be the use of studying physics if the mysteries were not the most important things to investigate? ~ Richard P. Feynman

The attempts to try to represent the electric field as the motion of some kind of gear wheels, or in terms of lines, or of stresses in some kind of material have used up more effort of physicists than it would have taken simply to get the right answers about electrodynamics. It is interesting that the correct equations for the behavior of light were worked out by MacCullagh in 1839. But people said to him: 'Yes, but there is no real material whose mechanical properties could possibly satisfy those equations, and since light is an oscillation that must vibrate in something, we cannot believe this abstract equation business'. ~ Richard Feynman

As revealed by physics, the truth is so remarkable, so amazing! ~ Richard P. Feynman

A scientist is never certain ... We absolutely must leave room for doubt or there is no progress and there is no learning. ~ Richard P. Feynman

How much do you value life?" "Sixty-four. ~ Richard Feynman

Agnostic for me would be trying to weasel out and sound a little nicer than I am about this. ~ Richard P. Feynman

This is not a new idea; this is the idea of the age of reason. This is the philosophy that guided the men that made the democracy that we live under. The idea that no one really knew how to run a government led to the idea that we should arrange a system by which new ideas could be developed, tried out, and tossed out if necessary, with more new ideas brought in - a trial and error system. ~ Richard Feynman

When we add all the numbers together, from all the different forms of energy, it always gives the same total. But as far as we know there are no real units, no little ballbearings. It ~ Richard Feynman

You know, the most amazing thing happened to me tonight ... I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing! ~ Richard Feynman

So we see that what looks like a dead, uninteresting thing - a glass of water with a cover, that has been sitting there for perhaps twenty years - really contains a dynamic and interesting phenomenon which is going on all the time. To ~ Richard Feynman

I have a friend who's an artist, and he sometimes takes a view which I don't agree with. He'll hold up a flower and say, "Look how beautiful it is," and I'll agree. But then he'll say, "I, as an artist, can see how beautiful a flower is. But you, as a scientist, take it all apart and it becomes dull." I think he's kind of nutty. [...] There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower. It only adds. I don't understand how it subtracts. ~ Richard Feynman

Damn deez doilies! ~ Richard Feynman

I've found out since that such people don't know what they're doing, and get insulted when you make some suggestion or criticism. ~ Richard Feynman

Figure 36. A "trick" can be played on Nature by slowing down the light that takes shorter paths: glass of just the right thickness is inserted so that all the paths will take exactly the same time. This causes all of the arrows to point in the same direction, and to produce a whopping final arrow-lots of light! Such a piece of glass made to greatly increase the probability of light getting from a source to a single point is called a focusing lens. ~ Richard Feynman

It is a great adventure to contemplate the universe, beyond man, to contemplate what it would be like without man, as it was in a great part of its long history and as it is in a great majority of places. When this objective view is finally attained, and the mystery and majesty of matter are fully appreciated, to then turn the objective eye back on man viewed as matter, to view life as part of this universal mystery of greatest depth, is to sense an experience which is very rare, and very exciting. It usually ends in laughter and a delight in the futility of trying to understand what this atom in the universe is, this thing - atoms with curiosity - that looks at itself and wonders why it wonders. Well, these scientific views end in awe and mystery, lost at the edge in uncertainty, but they appear to be so deep and so impressive that the theory that it is all arranged as a stage for God to watch man's struggle for good and evil seems inadequate.

Some will tell me that I have just described a religious experience. Very well, you may call it what you will. Then, in that language I would say that the young man's religious experience is of such a kind that he finds the religion of his church inadequate to describe, to encompass that kind of experience. The God of the church isn't big enough. ~ Richard P. Feynman

This conference was worse than a Rorschach test: There's a meaningless inkblot, and the others ask you what you think you see, but when you tell them, they start arguing with you! ~ Richard Feynman

For instance, the scientific article may say, 'The radioactive phosphorus content of the cerebrum of the rat decreases to one- half in a period of two weeks.' Now what does that mean?
It means that phosphorus that is in the brain of a rat - and also in mine, and yours - is not the same phosphorus as it was two weeks ago. It means the atoms that are in the brain are being replaced: the ones that were there before have gone away.
So what is this mind of ours: what are these atoms with consciousness? Last week's potatoes! They now can remember what was going on in my mind a year ago - a mind which has long ago been replaced. To note that the thing I call my individuality is only a pattern or dance, that is what it means when one discovers how long it takes for the atoms of the brain to be replaced by other atoms. The atoms come into my brain, dance a dance, and then go out - there are always new atoms, but always doing the same dance, remembering what the dance was yesterday. ~ Richard Feynman

The exception tests the rule. ~ Richard P. Feynman

For instance, the mass of an object changes when it moves, because of the conservation of energy. Because of the relation of mass and energy the energy associated with the motion appears as an extra mass, so things get heavier when they move. Newton ~ Richard Feynman

I'm trying to find out NOT how Nature could be, but how Nature IS. ~ Richard P. Feynman

I want to build a billion tiny factories, models of each other, which are manufacturing simultaneously ... The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. ~ Richard Feynman

We scientists are clever - too clever - are you not satisfied? Is four square miles in one bomb not enough? Men are still thinking. Just tell us how big you want it! ~ Richard P. Feynman

The most remarkable discovery in all of astronomy is that the stars are made of atoms of the same kind as those on the earth. ~ Richard P. Feynman

It always seems odd to me that the fundamental laws of physics, when discovered, can appear in so many different forms that are not apparently identical at first, but, with a little mathematical fiddling, you can show the relationship. ~ Richard P. Feynman

I have to disregard everybody else, and then I can do my own work. ~ Richard P. Feynman

If I say [electrons] behave like particles I give the wrong impression; also if I say they behave like waves. They behave in their own inimitable way, which technically could be called a quantum mechanical way. They behave in a way that is like nothing that you have seen before. ~ Richard P. Feynman

The universe is very large, and its boundaries are not known very well, but it is still possible to define some kind of a radius to be associated with it. ~ Richard P. Feynman

Once you have a computer that can do a few things - strictly speaking, one that has a certain 'sufficient set' of basic procedures - it can do basically anything any other computer can do. This, loosely, is the basis of the great principle of 'Universality'. ~ Richard P. Feynman

His colleague Richard Feynman wanted to call these new basic particles partons16, as in Dolly, but was over-ruled. Instead they became known as quarks. ~ Bill Bryson

So I have just one wish for you – the good luck to be somewhere where you are free to maintain the kind of integrity I have described, and where you do not feel forced by a need to maintain your position in the organization, or financial support, or so on, to lose your integrity. May you have that freedom. ~ Richard P. Feynman

Unless a thing can be defined by measurement, it has no place in a theory. And since an accurate value of the momentum of a localized particle cannot be defined by measurement it therefore has no place in the theory. ~ Richard P. Feynman

You have to have absolute confidence. Keep right on going, and nothing will happen. ~ Richard Feynman

I don't know what's the matter with people: they don't learn by understanding, they learn by some other way - by rote or something. Their knowledge is so fragile! ~ Richard Feynman

It's all generated, maybe, by the fact that the attitude of the populace is to try to find the answer instead of trying to find a man who has a way of getting at the answer. ~ Richard Feynman

The exception proves that the rule is wrong. That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong. ~ Richard Feynman

The adult Feynman asked: If all scientific knowledge were lost in a cataclysm, what single statement would preserve the most information for the next generations of creatures? How could we best pass on our understanding of the world? He proposed, "All things are made of atoms - little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another," and he added, "In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied. ~ Anonymous

What I cannot build. I do not understand. ~ Richard Feynman

While I am describing to you how Nature works, you won't understand why Nature works that way. But you see, nobody understands that. ~ Richard P. Feynman

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty - some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don't know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question - to doubt - to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained. ~ Richard P. Feynman

I would rather have questions that can't be answered than answers that can't be questioned. ~ Richard Feynman

This is not very important what I'm doing. I'm just proving something. ~ Richard P. Feynman

The internal machinery of life, the chemistry of the parts, is something beautiful. And it turns out that all life is interconnected with all other life. ~ Richard P. Feynman

But the real glory of science is that we can find a way of thinking such that the law is evident. ~ Richard P. Feynman